precision mediump float;
varying vec4 vDiffuse;//接收从顶点着色器过来的散射光分量
void main(){
   vec4 finalColor=vec4(1.0);
   //给此片元颜色值
   gl_FragColor=finalColor*vDiffuse+finalColor*vec4(0.15,0.15,0.15,1.0);
}